Abrading tool



Aug. 22, 1961 H. GxANA-rAslo 2,996,852

ABRADING TOOL.

Filed June 6, 1958 3 Sheets-Sheet 1 INVENTO'R.

HENRY L. GIANATASlO Fil-EL( E- Aug. 22, 1961 H. L. GIANATAslo ABRADING TOOL 3 Sheets-Sheet 2 Filed June 6, 1958 {Illu/ll) INVENTOR. HENRY L. GIANATAslo BY M HEL/5 Aug. 22, 1961 H. L. GIANATASIO ABRADING TOOL 3 Sheets-Sheet 3 Filed June 6, 1958 INVENTOR. HENRY L. @ANN-As@ gares This invention relates to an abrading tool.

More particularly, this invention relates to an abrading tool embodying an abrasive `coated disc and mounting means therefor by which the new abrading tool may be detachably attached to the chuck of an electric drill, or the like, to enable the said abrasive disc to be rotated in contact with a metal or other surface to be abraded.

An object of the present invention is to provide a new and improved abrading tool including an abrasive coated disc and a shaft or mandrel therefor which is adapted to be detachably attached to the chuck of an electric drill, or the like, together with novel means for mounting the abrasive coated disc on the mandrel.

An additional object of the invention is to provide in the new abrading tool a novel construction and arrangement for detachably fastening the abrasive coated disc on the mandrel or shaft which, in turn, is adapted to be detachably attached to the chuck of an electric drill, or the like.

Other objects will appear hereinafter.

In the drawings:

FIG. 1 is an elevational view showing a preferred form of the present invention;

FIG. 2 is a central vertical sectional view partly in elevation;

FIG. 3 is a top plan view;

FIG. 4 is a bottom plan vieW;

FIG. 5 is an enlarged fragmentary sectional detail view showing the novel means for mounting the abrasive coated disc on the shaft or mandrel;

FIG. 6 is a sectional top plan view on line 6 6 in FIG. 2;

FIG. 7 is a sectional bottom plan view on line 7-7 in FIG. 5;

FIG. 8 is an elevational view of a modified form of construction;

FIG. 9 is a view partly in elevation and partly in section, of the modified form of construction illustrated in FIG. 8;

FIG. l0 is an enlarged fragmentary vertical sectional view of the 4construction shown in FIGS. 8 and 9;

FIG. ll is an elevational vView illustrating a further modified form of construction;

FIG. 12 is a view partly in elevation and partly in section, of the form of construction illustrated in FIG. 11;

FIG. 13 is an enlarged fragmentary sectional view of the construction shown in FIGS. l1 and l2;

FIG. 14 is an elevational view of another modified form of construction;

FIG. 15 is a view, partly in elevation and partly in section, of the modified form of construction illustrated in FIG. 14;

FIG. 16 is an enlarged fragmentary sectional detail view of the construction shown in FIGS. 14 and 15;

FIG. 17 is a sectionalplan View on line 17-17 in FIG. 14;

FIG. 18 is an elevational view of a further modified form of construction;

FIG. 19 is a view partly in elevation and partly in section, of the modified form of construction illustrated in FIG. 18; and

FIG. 20 is an enlarged fragmentary sectional detail View of the construction illustrated in FIGS. 19 and 20.

236,852 Patented Aug. Z2, 1961 ice A preferred embodiment of the present invention is shown in FIGS. l to 7, inclusive, of the drawings, Where it is generally indicated at 10, and includes a mandrel or shaft 11 having a reduced diameter externally threaded extension i12 at the outer end thereof providing a surrounding shoulder. The mandrel or shaft 11 has a resilient generally conical-shaped rubber mounting and re-enforcing backing block 13 fastened thereto, as by molding the rubber mounting block 13 on an enlarged portion 14 of the mandrel or shaft 11. This rubber mounting and re-enforcing backing block 13 has an enlarged flanged portion 15 at its outer end and in which a centrally arranged recess 16 is provided, for a purpose which will be explained presently.

The new abrading tool includes a re-enforcing backing sheet 17 of relatively stiff paperboard, or like material, and it also embodies an abrasive coated disc '18 which is adhesively secured to the outer surface of the backing disc 17 by means of a suitable adhesive 19. The abrasive coated disc 18 has an abrasive coated outer surface 20 (FIG. 5).

The new abrading tool 10 includes novel means for detachably attaching the abrasive coated disc 1S, and its attached re-enforcing backing sheet 17, to the lower externally threaded extension 12 of the shaft or mandrel 11. This novel attaching means includes a formable metal rivet body 21 which has a threaded centrally arranged bore 22 which is adapted to receive the externally threaded reduced extension 12 of the mandrel or shaft 11.

In the practice of the present invention the rubber mounting and backing block 13 may be molded upon the enlarged portion 14 of the mandrel or shaft 11, in the position shown, or it may be adhesively mounted thereon, as desired.

Likewise, in the practice of the present invention the formable rivet body 21 includes a neck portion, as shown, which is inserted through a centrally arranged cut-out opening 23 which is formed in the re-enforcing backing disc 17 and the end of the neck portion is then formed, under pressure, to provide a clamping flange 24 which is formed over the marginal edge portion of that part of the re-enforcing backing disc 17 which defines the centrally arranged opening 23 therein for the reception of the rivet body neck portion, as best shown in FIG. 5. The abrasive coated disc 13 is then adhesively secured, at its inner surface, to the outer surface of the backing disc 17, by means of a suitable adhesive 19, with the clamping ange portion 24 of the rivet body neck lportion extending under that portion of the backing disc 17 which defines the marginal edge portion of the central opening 23 in the re-enforcing backing disc 17. This arrangement is such that the centrally arranged portion 25 of the abrasive coated disc 18 is deformed somewhat out of the plane of the body of the abrasive coated disc 18, as best shown in FIG. 5. Y

When the parts are thus arranged the abrasive coated disc 18, with its re-enforcing backing disc 17, and with the formed internally threaded rivet body 21 attached thereto, as shown, may be detachably attached to the mandrel or shaft 11 by merely threading the rivet body 2.1 on to the reduced externally threaded portion .12 of the mandrel or shaft 11, so that the parts take the assembled position shown in FIGS. 1, 2 and 5 of the drawings. When the rivet body is so attached the outer surface thereof will bear against the mandrel shoulder at the inner end of the threaded extension 12. 'Ihe inner surface of the rivet body at the inner end of the neck will engage the adjacent surface of the backing disc 17 and be coplanar with the end surface of the backing block as shown.

"The thus assembled abrading tool 10 may then be attached to the chuck of an electric drill, or other suitable rotary power tool, by inserting the shaft or mandrel 11 therein, whereupon the abrasive coated outer surface 20 of the abrasive coated disc 18 may be then rotated in contact with the work or surface to be abraded. During this operation the rubber re-enforcing backing block 13 and its enlarged flange portion 15 provide a re-enforcing backing and support for the abrasive coated disc 18 and its re-enforcing backing disc 17 and the flange portion 15' of the rubber re-enforcing block 13 absorbs the bending and other stresses and forces which result when the tool is applied to the work and thus prevents those bending stresses and forces from being applied to the clamping ange 24 of the rivet body 21 which would otherwise tend to crack the flange [24 of the rivet from the body 21 thereof.

After the abrasive coated surface 20 of the disc 18 has been worn the abrasive coated disc 18, and its attached re-enforcing backing disc 17, and rivet body 21, may be readily removed from the mandrel or shaft 11 by merely unscrewing the rivet body 21 from the externally threaded outer portion 12 of the mandrel or shaft 11 and replacing same with a new assembly of the abrasive coated disc 18 and attached re-enforcing backing disc 17 and rivet body 21.

A modification of the invention is illustrated in FIGS. 8 to l0, inclusive, and those parts thereof which are similar to corresponding parts of the invention which are embodied in the form of the invention shown in FIGS. l to 7, inclusive, have been given similar reference numerals followed by the additional and distinguishing reference character 61.

The form of the invention shown in FIGS. 8 to 10, inclusive, is similar to the form of the invention illustrated in FIGS. 1 to 7, inclusive, except that in this form of the invention the abrasively coated paper or like disc 18a is not extended over the clamping flange 24a of the threaded rivet body 21a, but instead the center portion of the abrasively coated paper disc 18a extends under the clamping flange 24a of the threaded rivet body 21a.

A further modification of the invention is shown in FIGS. 11 to 13, inclusive, of the drawings, and those parts of the invention illustrated in FIGS. l to 7, inclusive, have been given the same reference numerals followed by the additional and distinguishing reference character b.

The modified form of construction shown in FIGS. ll to 13, inclusive, is substantially similar to the form of construction shown in FIGS. 8 to l0, inclusive, except that in this form of the invention the intermediate layer or coating of adhesive 19a, which bonds the adhesively coated outer paper or like disc 18a to the backing disc 17a, in the form of construction shown in FIGS. 8 to l0, inclusive, is eliminated and the abrasively coated paper or like disc 18b is merely backed up by the backing disc 17b without being adhesively secured or bonded thereto. The form of construction illustrated in FIGS. ll to 13, inclusive has the advantage of being somewhat more economical to manufacture, than the forms shown in FIGS. 1 to 10, inclusive, in that it eliminates the need for the use of an adhesive coating between the abrasive coated paper or like disc 18b and the backing disc 17b and the expense involved in the additional operation required in connection therewith.

A further modification of the invention is illustrated in FIGS. 14 to 16, inclusive, of the drawings, and in this form of the invention those parts which are similar to corresponding parts of the invention shown in FIGS. l to 7, inclusive, have been given the same reference numerals followed by the additional and distinguishing reference character c.

The form of the invention illustrated in FIGS. 14 to 16, inclusive, is similar to the form of the invention illustrated in FIGS. ll to 13, inclusive, but differs rtherefrom in a manner which will be described presently.

Thus, in the form of construction illustrated in FIGS. 14 to 16, inclusive, the backing disc 17e is provided with a series of radially extending slits 27 which extend inwardly from the peripheral or marginal edge portion of the backing disc 17C to a point disposed somewhat radially outwardly of the center thereof, thus dividing the backing ydisc 17e into a series of radial segments 26.

The form of construction illustrated in FIGS. 14 to l7, inclusive, has the advantage which resides in the fact that the radial segments 26 of the backing disc 17C ex readily when the tool is in use and the coated abrasive disc 18C is pressed against the Work to be abraded, thereby enabling the abrasive coated disc 18C to flex more readily and to conform to the shape of the surface or the work which is being abraded.

Another modification of the invention is illustrated in FIGS. 18 to 20, inclusive, of the drawings, and in this form of construction those parts which correspond to similar parts of the invention illustrated in FIGS. l to 7, inclusive, of the drawings, have been given similar reference numerals followed by the additional and distinguishing reference character d.

'In the form of the invention illustrated in FIGS. 18 to 20, inclusive, of the drawings, the backing disc employed in the other forms of the invention, previously described, is eliminated entirely, and the abrasively coated disc 18d is attached directly to the threaded rivet body 21d by swedging the outer marginal clamping flange portion 24d of the rivet body neck portion over that portion of the abrasively coated disc 18d which defines the central aperture 23d therein and through which the rivet body neck portion is extended.

The form of the invention, illustrated in FIGS. 18 to 20, inclusive, has the advantage over the forms of the invention illustrated in FIGS. l to 17, inclusive, in that it is somewhat less expensive to manufacture and in that it eliminates the necessity for and the expense involved in the use of a backing disc for the abrasive coated disc.

It will thus be seen from the foregoing description, considered in connection with the accompanying drawings, that the present invention provides a new and irnproved abrading tool, having the desirable advantages and characteristics, and accomplishing its objects, including those hereinbefore pointed out and others which are inherent in the invention.

I claim:

1. An abrading tool comprising a mandrel for attachrnent at one end to a rotary power driven tool and having a reduced threaded extension at its other end providing an annular shoulder, a resilient ybacking block encircling and secured to said other end of the mandrel and having a bottom face provided with a central recess, a metal rivet body having a threaded central bore mounted on said extension and located in said recess and having an outer surface `bearing against the annular shoulder of the mandrel, the rivet body having an inner surface coplanar with the said bottom face of the backing block, the rivet body having a reduced neck extending from the said inner surface and terminating in a lateral clamping flange, a backing disc having a central opening through which said reduced neck extends, the disc having a plane top surface around said central opening bearing against said bottom face of the backing block and against said inner surface of the rivet body, a portion of the backing disc around said opening being secured between said inner surface of the rivet body and clamping flange, the said bottom face of the backing `block engaging said plane surface of the backing disc over a substantial radial extent, and an abrasive coated disc secured to the bottom surface of the backing disc.

2. The invention according to` claim l, wherein said abrasive coated disc has a central opening through which said reduced neck extends and said clamping ange bearing against the abrasive coated surface of the abrasive discs.

3. The invention according to claim 1, wherein the abrasive coated disc covers the clamping ange.

4. The invention according to claim 1, wherein said flexible backing `disc has a series of radially extending slits therein extending radially Ifrom the outer edge thereof toward and terminating short of the said central opening therein and dividing said backing disc into a series of radially arranged exible segments.

References Cited in the le of this patent UNITED STATES PATENTS Morrison Apr. 15, 1890 Stratford Oct. 9, 1928 Mitschange et al Feb. 7, 1939 Field Nov. 27, 1956 Larson Feb. 19, 1957 Seal July 15, 1958 

